Power generation system for gas-fired appliances

ABSTRACT

A power generation system for use with a gas fired appliance including a main burner and a gas supply line includes a pilot burner assembly for igniting gas supplied to the main burner and a controller. The pilot burner assembly includes a thermo-electric device configured to convert thermal energy into electrical energy, and a pilot guard. The pilot guard has a first end defining a gas inlet and a second end defining a gas outlet. The controller is configured to receive a signal from the thermo-electric device, and control the supply of gas to the main burner based on the signal. The controller is powered by electrical energy generated by the thermo-electric device. The thermo-electric device has an internal resistance matched to a load resistance of the controller to facilitate maximum power transfer between the thermo-electric device and the controller.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/266,101, filed Apr. 30, 2014, the disclosure of which is herebyincorporated by reference in its entirety.

FIELD

The field of the disclosure relates generally to gas-fired appliances,and more particularly, to pilot burner assemblies for use in millivoltcontrolled gas fired appliances.

BACKGROUND

Gas fired appliances, such as residential gas-fired water heaters, ofteninclude a main gas burner to provide heat for the appliance and a pilotburner assembly that provides a standing pilot flame to ignite the maingas burner (e.g., for the first time or if the main burner flame goesout). In the case of water heaters, a main gas burner is used to heatwater within a water tank of the water heater. A thermostat is typicallyprovided to control the temperature of the water inside the tank andtypically may be set within a particular range (e.g., warm, hot or veryhot). A pilot burner assembly provides a standing pilot flame to ignitethe main gas burner. Further, water heaters typically include athermocouple device to detect whether the pilot flame is present. Thethermocouple device is typically electrically connected to a gas valvewhich supplies gas to the main burner of the water heater. The heatgenerated by the pilot flame creates an electrical current or signal inthe thermocouple that keeps the gas valve open. When the pilot flamegoes out, no current or signal is generated by the thermocouple, causingthe gas valve to close.

Pilot burner assemblies typically include a burner tube assembly throughwhich gas is fed and an igniter to ignite the gas supplied through theburner tube assembly. Known burner tube assemblies typically haveseveral discrete components used to connect the burner tube assembly toa gas supply line, and to mount the pilot burner assembly within thewater heater system. Further, such components often require preciseconnecting procedures, such as staking or tightening according to atorque specification. Assembly of such pilot burner assemblies is thustimely and complicated.

Additionally, at least some pilot burner assemblies include a pilot hoodas a separate component from the burner tube assembly, furtherincreasing the material cost and time needed to assemble such pilotburner assemblies. Moreover, the spark gap between the igniter and anigniting component (e.g., the pilot hood) in such pilot burnerassemblies often requires adjustment following assembly of the pilotburner assembly to ensure proper operation. In some pilot burnerassemblies, the proper spark gap is obtained by bending the ignitertoward or away from the igniting component, such as the pilot hood,until the proper spark gap is obtained. While such bending may providethe desired spark gap, it is often difficult, time-consuming, andcostly. Further, the igniter and the ignition component are susceptibleto rotation, bending, and other movement during subsequent handling ofthe burner assembly, which may alter the size of the spark gap. Further,the resulting spark gap between the igniter and the igniting componentis often unreliable as the arc path may not consistently intersect theair-fuel mixture discharged from the burner tube.

Moreover, thermocouples used in known pilot burner assemblies are notoptimized for the systems in which they are used, thus resulting inpower efficiency losses.

This Background section is intended to introduce the reader to variousaspects of art that may be related to various aspects of the presentdisclosure, which are described and/or claimed below. This discussion isbelieved to be helpful in providing the reader with backgroundinformation to facilitate a better understanding of the various aspectsof the present disclosure. Accordingly, it should be understood thatthese statements are to be read in this light, and not as admissions ofprior art.

SUMMARY

In one aspect, a pilot burner assembly for use with a gas firedappliance is provided. The pilot burner assembly includes a bracket, athermo-electric device configured to be connected to the bracket, and aunitary pilot guard. The bracket includes a first plate and a secondplate spaced from the first plate. Each of the first and second plateshave a pilot guard aperture defined therein. The pilot guard has a firstend defining a gas inlet configured to receive a gas supply line, and asecond end defining a gas outlet. The pilot guard includes an elongatebody and a pilot hood disposed at the second end, and is configured beinserted into the pilot guard apertures. The pilot guard furtherincludes a first retention element configured to cooperate with a secondretention element on the gas supply line to maintain a connectionbetween the pilot guard and the gas supply line.

In another aspect, a power generation system for use with a gas firedappliance including a main burner and a gas supply line is provided. Thepower generation system includes a pilot burner assembly for ignitinggas supplied to the main burner and a controller. The pilot burnerassembly includes a thermo-electric device configured to convert thermalenergy into electrical energy, and a pilot guard. The pilot guard has afirst end defining a gas inlet and a second end defining a gas outlet.The pilot guard includes an elongate body and a pilot hood disposed atthe second end. The controller is configured to receive a signal fromthe thermo-electric device, and control the supply of gas to the mainburner based on the signal. The controller is powered by electricalenergy generated by the thermo-electric device. The thermo-electricdevice has an internal resistance matched to a load resistance of thecontroller to facilitate maximum power transfer between thethermo-electric device and the controller.

In yet another aspect, a method of assembling a pilot burner assemblyfor use with a gas fired appliance including a main burner and a gassupply line including an outlet orifice is provided. The pilot burnerassembly includes a bracket, a thermo-electric device, and a pilotguard. The bracket includes a first plate and a second plate, eachhaving a pilot guard aperture defined therein. The pilot guard has afirst end defining a gas inlet and a second end defining a gas outlet,and includes an elongate body and a pilot hood disposed at the secondend. The pilot guard further includes a first retention element, and thegas supply line further includes a second retention element. The methodincludes inserting the outlet orifice through at least one of the pilotguard apertures defined in the first plate and the second plate, andinserting the pilot guard through each pilot guard aperture such thatthe first retention element engages the second retention element tomaintain a connection between the pilot guard and the gas supply line.

Various refinements exist of the features noted in relation to theabove-mentioned aspects. Further features may also be incorporated inthe above-mentioned aspects as well. These refinements and additionalfeatures may exist individually or in any combination. For instance,various features discussed below in relation to any of the illustratedembodiments may be incorporated into any of the above-described aspects,alone or in any combination.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cut-away view of a gas fired appliance shown in the form ofa water heater system, the water heater system including a main burnerand one embodiment of a pilot burner assembly for igniting the mainburner.

FIG. 2 is a perspective view of the pilot burner assembly shown in FIG.1 in an assembled configuration.

FIG. 3 is an exploded view of the pilot burner assembly shown in FIG. 2.

FIG. 4 is a perspective view of a mounting bracket included in the pilotburner assembly shown in FIG. 2.

FIG. 5 is a perspective view of the pilot burner assembly shown in FIG.2 in a partially assembled configuration.

FIG. 6 is an enlarged perspective view of the pilot burner assemblyshown in FIG. 5.

FIG. 7 is a top plan view of the pilot burner assembly shown in FIG. 2.

FIG. 8 is another enlarged perspective view of the pilot burner assemblyshown in FIG. 2.

FIG. 9 is another enlarged perspective view of the pilot burner assemblyshown in FIG. 2.

FIG. 10 is a perspective view of another embodiment of a pilot burnerassembly suitable for use in the water heater system of FIG. 1.

DETAILED DESCRIPTION

Referring to FIG. 1, a gas fired appliance illustrated in the form of awater heater system for heating and storing water is indicated generallyat 20. Water heater system 20 generally includes a storage tank 22 and agas-fired burner assembly 30 positioned beneath storage tank 22 forheating water supplied to and stored in storage tank 22. Storage tank 22receives cold water via a cold water inlet 26 in a bottom portion 28 ofstorage tank 22. Cold water entering bottom portion 28 of storage tank22 is heated by burner assembly 30. Water that is heated leaves storagetank 22 via a hot water outlet pipe 34. Combustion gases from burnerassembly 30 leave water heater system 20 via a flue 36.

Burner assembly 30 includes a main burner 38 connected to a gas supplyvia a gas supply line 40, a controller 44 for controlling the supply ofgas to main burner 38, and a pilot burner assembly 100 for igniting mainburner 38. As described in more detail herein, pilot burner assembly 100is also configured to detect whether a pilot flame is present orextinguished, and communicate with controller 44 via connection 42 tocontrol the supply of gas to main burner 38 (e.g., by shutting off thesupply of gas if no pilot flame is detected).

Referring to FIGS. 2 and 3, the pilot burner assembly 100 includes apilot guard 102, an igniter 104, a thermo-electric device 106, and amounting bracket 108. The illustrated pilot burner assembly 100 alsoincludes a gas supply line 110 that facilitates quick and easy assemblyof pilot burner assembly 100, as described in more detail herein.

Gas is supplied to pilot guard 102 via gas supply line 110, and is mixedwith air within pilot guard 102 before being discharged at a gas outlet112 of pilot guard 102. Igniter 104 is connected to a voltage source(not shown) via connection line 114 which provides sufficient electricalenergy to create an electrical arc or spark between igniter 104 andpilot guard 102 and ignite the air-fuel mixture. The ignition of theair-fuel fuel mixture creates a flame, also referred to herein as apilot flame or a pilot light, which is directed towards thethermo-electric device 106 by pilot guard 102. Thermo-electric device106 converts thermal energy from the pilot flame into an electriccurrent or signal, and outputs the current or signal to controller 44(shown in FIG. 1) via connection 42. Pilot guard 102, igniter 104, andthermo-electric device 106 are each connected to mounting bracket 108,which maintains the position of pilot guard 102, igniter 104, andthermo-electric device 106 relative to one another. Mounting bracket 108is mounted to water heater system 20 to maintain the position of pilotguard 102, igniter 104, and thermo-electric device 106 relative to othercomponents of water heater system 20, such as main burner 38. Asdescribed in more detail herein, the components of pilot burner assembly100 include various retention elements that enable relatively quick andsimple assembly of pilot burner assembly 100 as compared to conventionalsystems.

With additional reference to FIG. 4, mounting bracket 108 includes afirst plate 116, a second plate 118 spaced from first plate 116, and athird plate 120 interconnecting first plate 116 and second plate 118.First plate 116 includes a pilot guard aperture 122 (broadly, a firstaperture) configured to receive pilot guard 102 therein, an igniteraperture 124 (broadly, a second aperture) configured to receive igniter104 therein, and a thermo-electric device aperture 126 (broadly, a thirdaperture) configured to receive thermo-electric device 106 therein.Second plate 118 similarly includes a pilot guard aperture 128configured to receive pilot guard 102 therein, an igniter aperture 130configured to receive igniter 104 therein, and a thermo-electric deviceaperture 132 configured to receive thermo-electric device 106 therein.Further, first plate 116 and second plate 118 each include a respectivefirst side 134, 136, and an opposing second side 138, 140.

In the illustrated embodiment, first plate 116 and second plate 118 areoriented substantially parallel to one another, and third plate isoriented substantially perpendicular to first plate 116 and second plate118. In other suitable embodiments, first plate 116 and second plate 118may be oriented other than substantially parallel to one another, andthird plate 120 may be oriented other than substantially perpendicularto first plate 116 and second plate 118.

Pilot guard aperture 122 defined in first plate 116 is sized and shapedto receive pilot guard 102 therein. More specifically, the diameter ofpilot guard aperture 122 is substantially equal to an outer diameter ofpilot guard 102. Pilot guard aperture 122 also includes a slotted region142 that enables one or more retention elements of pilot guard 102 topass therethrough when pilot burner assembly 100 is assembled.

Pilot guard aperture 128 defined in second plate 118 is sized and shapedto receive pilot guard 102 therein. More specifically, the diameter ofpilot guard aperture 128 is substantially equal to an outer diameter ofpilot guard 102. Pilot guard aperture 128 also includes a slotted region144 that enables one or more retention elements of pilot guard 102 topass therethrough when pilot burner assembly 100 is assembled. Further,second plate 118 includes a retaining ledge 146 that extends into pilotguard aperture 128 and at least partially defines slots 148 along theouter perimeter of pilot guard aperture 128. As described in more detailherein, retaining ledge 146 and slots 148 cooperate with one or moreretention elements of pilot guard 102 and gas supply line 110 to enablerelatively quick and simple assembly of pilot burner assembly 100. Inthe illustrated embodiment, retaining ledge 146 includes two retainingprotrusions 150 spaced circumferentially around pilot guard aperture128. Further, in the illustrated embodiment, retaining protrusions 150protrude into pilot guard aperture 128 from diametrically opposed sidesof pilot guard aperture 128. In other suitable embodiments, retainingledge 146 may include any suitable number of retaining protrusions, suchas one, three, and four protrusions, arranged in any suitableconfiguration that enables pilot burner assembly 100 to function asdescribed herein.

Second plate 118 also includes a locking protrusion 152 that protrudesinto pilot guard aperture 128. Locking protrusion 152 is spacedcircumferentially from retaining protrusions 150 around pilot guardaperture 128. As described in more detail herein, locking protrusion 152is configured to cooperate with a retention element on pilot guard 102to inhibit rotation of pilot guard 102 relative to bracket 108 whenpilot burner assembly 100 is assembled. The illustrated embodimentincludes one locking protrusion 152, although other suitable embodimentsmay include more than one locking protrusion, such as two, three, four,or any other suitable number of locking protrusions.

Each retaining protrusion 150 and locking protrusion 152 extends adistance along the perimeter of pilot guard aperture 128 (i.e., in acircumferential direction), referred to as the width of the respectiveprotrusion. As shown in FIG. 4, retaining protrusions 150 have a greaterwidth than locking protrusion 152.

As noted above, slots 148 are provided along the outer perimeter ofpilot guard aperture 128. Slots 148 are defined by retaining protrusions150 and/or locking protrusion 152, and are configured (i.e., sized andshaped) to receive and/or retain retention elements on gas supply line110 and pilot guard 102, as described in more detail herein. Theillustrated embodiment includes three slots 148. Further, in theillustrated embodiment, one slot 148 is defined by two retainingprotrusions 150, and two slots 148 are defined by one retainingprotrusion 150 and locking protrusion 152. In other suitableembodiments, pilot burner assembly 100 may include any suitable numberof slots 148 arranged in any suitable configuration that enables pilotburner assembly 100 to function as described herein. As described inmore detail herein, the configuration of pilot guard aperture 128,retaining ledge 146, slots 148, retaining protrusion 150 and lockingprotrusion 152 facilitates maintaining the orientation of pilot guard102 relative to igniter 104 and thermo-electric device 106.

Each igniter aperture 124, 130 is sized and shaped to receive igniter104 therein. More specifically, each igniter aperture 124, 130 has adiameter substantially equal to an outer diameter of igniter 104. In theillustrated embodiment, first plate 116 includes a retaining ring 154surrounding igniter aperture 124. Retaining ring 154 is configured toprovide a connection between mounting bracket 108 and igniter 104. Inthe illustrated embodiment, for example, retaining ring 154 includesresilient fingers 156 extending towards the center of igniter aperture124. In the illustrated embodiment, retaining ring 154 includes threeresilient fingers 156, although retaining ring 154 may include less thanor more than three resilient fingers 156. In one suitable embodiment,for example, retaining ring 154 includes a single, continuous, resilientfinger forming a solid, resilient ring surrounding igniter aperture 124.

Each resilient finger 156 is biased towards the center of igniteraperture 124 such that when igniter 104 is inserted through igniteraperture 124, resilient fingers 156 provide a press-fit connectionbetween mounting bracket 108 and igniter 104. In the illustratedembodiment, resilient fingers 156 extend from first side 134 of firstplate 116 and away from second plate 118. In other suitable embodiments,resilient fingers 156 may extend from second side 138 of first plate 116and towards second plate 118.

Each thermo-electric device aperture 126, 132 is sized and shaped toreceive thermo-electric device 106 therein. More specifically, eachthermo-electric device aperture 126, 132 has a diameter substantiallyequal to an outer diameter of thermo-electric device 106. In theillustrated embodiment, first plate 116 includes a retaining ring 158surrounding thermo-electric device aperture 126. Retaining ring 158 isconfigured to provide a connection between mounting bracket 108 andthermo-electric device 106. In the illustrated embodiment, for example,retaining ring 158 includes resilient fingers 160 extending towards thecenter of thermo-electric device aperture 126. In the illustratedembodiment, retaining ring 158 includes three resilient fingers 160,although it is understood that retaining ring 158 may include less thanor more than three resilient fingers 160. In one suitable embodiment,for example, retaining ring 158 includes a single, continuous, resilientfinger forming a solid, resilient ring surrounding thermo-electricdevice aperture 126.

Each resilient finger 160 is biased towards the center ofthermo-electric device aperture 126 such that when thermo-electricdevice 106 is inserted through thermo-electric device aperture 126,resilient fingers 160 provide a press-fit connection between mountingbracket 108 and thermo-electric device 106. In the illustratedembodiment, resilient fingers 160 extend from first side 134 of firstplate 116 and away from second plate 118. In other suitable embodiments,resilient fingers 160 may extend from second side 138 of first plate 116and towards second plate 118.

Referring again to FIGS. 2 and 3, thermo-electric device 106 isconfigured to detect the presence of a pilot flame by converting thermalenergy from the pilot flame into an electric current or signal, andoutputting the current or signal to controller 44 (shown in FIG. 1) viaconnection 42. In the absence of a current or signal fromthermo-electric device (e.g., when pilot flame is extinguished),controller 44 is configured to shut off the supply of gas to main burner38. When pilot burner assembly 100 is assembled (shown in FIG. 2),thermo-electric device 106 is received within thermo-electric deviceapertures 126, 132 (shown in FIG. 3) in mounting bracket 108, andconnected to mounting bracket 108 by a press-fit connection betweenretaining ring 158 (shown in FIG. 4) and thermo-electric device 106.

Thermo-electric device 106 may be any suitable thermo-electric device106 that enables pilot burner assembly 100 to function as describedherein including, for example, a thermocouple or a thermopile (i.e., aplurality of thermocouples connected in series or parallel). In theillustrated embodiment, thermo-electric device 106 is a thermopile, and,more specifically, a millivolt thermopile.

Further, in the illustrated embodiment, thermo-electric device 106 isused as a power supply for controller 44 (shown in FIG. 1). That is,thermo-electric device 106 acts as a thermogenerator (also known as athermoelectric generator), converting thermal energy from the pilotflame into electrical energy to power controller 44. Accordingly, pilotburner assembly 100 and controller 44 are collectively referred toherein as a power generation system.

Thermo-electric device 106 is configured to maximize power transferbetween thermo-electric device 106 and controller 44 (shown in FIG. 1).More specifically, thermo-electric device 106 has an internal resistancethat is matched to (e.g., substantially equal to) a load resistance, orimpedance, of controller 44. In some embodiments, the load resistance ofcontroller 44 may vary depending upon an operational state of controller44. For example, controller 44 may have a first load resistance during acharging state (broadly, a first state) in which capacitors withincontroller 44 are charged, and a second load resistance during a standbystate (broadly, a second state). The load resistance of controller 44 inthe charging state may be higher or lower than the load resistance inthe standby state. Further, the power consumption of controller 44 maybe different depending upon the operational state of controller 44. Forexample, the power consumption of controller 44 may be higher during thecharging state, and lower during the standby state. Accordingly, theinternal resistance of thermo-electric device 106 may be matched to aload resistance of controller 44 to facilitate maximum power transferbetween thermo-electric device 106 and controller 44. In one suitableembodiment, for example, the internal resistance of thermo-electricdevice 106 is substantially equal to the load resistance of controller44 corresponding to the maximum power consumption operational state ofcontroller 44 (e.g., a charging state). In another suitable embodiment,the internal resistance of thermo-electric device 106 is between a firstload resistance of controller 44 corresponding to a first operationalstate (e.g., a charging state) and a second load resistance ofcontroller 44 corresponding to a second operational state (e.g., astandby state). The value of the internal resistance of thermo-electricdevice 106 may vary depending on the type of controller used forcontroller 44. In one suitable embodiment, the internal resistance ofthermo-electric device is between about 2 Ohms (Ω) and about 9Ω, moresuitably between about 4Ω and about 8Ω and, even more suitably, betweenabout 4.5Ω and about 5.5Ω.

Still referring to FIGS. 2 and 3, igniter 104 is configured to providean ignition source to ignite the air-fuel mixture fed through gas outlet112. When pilot burner assembly 100 is assembled (shown in FIG. 2),igniter 104 is received in igniter apertures 124, 130 (shown in FIG. 3)in mounting bracket 108, and connected to mounting bracket 108 by apress-fit connection between retaining ring 154 (shown in FIG. 4) andigniter 104.

Igniter 104 may be any suitable igniter 104 that enables pilot burnerassembly 100 to function as described herein, including, for example apiezo-electric igniter. In the illustrated embodiment, igniter 104includes an electrode 162 surrounded by an insulating sleeve 164 toprovide insulation between electrode 162 and mounting bracket 108.Electrode 162 includes an electrode tip 166 that protrudes out of oneend of insulating sleeve 164. Electrode tip 166 is positioned asufficient distance from mounting bracket 108 (specifically, first plate116 of mounting bracket 108) to prevent an electrical arc or sparkbetween electrode tip 166 and mounting bracket 108 through the open airor by over-surface ignition along the surface of the insulating sleeve164. Igniter 104 (more specifically, insulating sleeve 164) may have aconstant diameter as shown in FIGS. 2 and 3, or igniter 104 may beoutwardly tapered along a longitudinal axis 168 of igniter 104 to reducethe press-fit distance of igniter 104 within mounting bracket 108.

Gas supply line 110 is configured to supply gas to pilot guard 102. Whenpilot burner assembly 100 is assembled, gas supply line 110 is fluidlyconnected to a gas source (not shown) at one end (i.e., an inlet end),and fluidly connected to pilot guard 102 at an outlet end 170 (shown inFIG. 3) of gas supply line 110. As shown in FIG. 3, gas supply line 110includes an outlet orifice 172 disposed at outlet end 170 configured tobe connected to mounting bracket 108 and pilot guard 102. Outlet orifice172 may be connected to gas supply line 110 by any suitable connectionthat enables gas supply line 110 to function as described herein. In theillustrated embodiment, for example, outlet orifice 172 is press-fitonto the outer diameter outlet end 170 of gas supply line 110 and stakedto gas supply line 110 (indicated by an indented region 173 on outletorifice 172 in FIG. 3). Outlet orifice 172 may also be press-fit to theinner diameter of outlet end 170. Additionally or alternatively, outletorifice 172 may be welded to outlet end 170 of gas supply line 110.

With additional reference to FIGS. 5 and 6, outlet orifice 172 isreceived through pilot guard aperture 128, and is connected to mountingbracket 108 by retaining ledge 146 (shown in FIG. 4). Outlet orifice 172includes a plurality of retainers 174 (shown in FIG. 6) extendingradially outward from outlet orifice 172. Retainers 174 are configured(i.e., sized and shaped) to be received through slots 148 (shown in FIG.4) in second plate 118 and engage retaining ledge 146 (specifically,retaining protrusions 150, shown in FIG. 4) to inhibit axial movement ofgas supply line 110 in a first direction, indicated by arrow 109 in FIG.5. Retainers 174 are also configured to cooperate with retentionelements on pilot guard 102 to inhibit rotation of outlet orifice 172and inhibit axial movement of gas supply line 110 in a second direction,indicated by arrow 111 in FIG. 5, opposite first direction 109.Retainers 174 may also be configured to be received within pilot guardaperture 122.

The configuration of mounting bracket 108 and outlet orifice 172facilitates relatively quick and simple assembly of pilot burnerassembly 100 as compared to conventional systems using, for example,threaded connecting members. Specifically, outlet orifice 172 isconfigured to be connected to mounting bracket 108 by inserting outletorifice 172 through pilot guard aperture 128 (shown in FIG. 4), androtating outlet orifice 172 by less than 180 degrees about alongitudinal axis 176 (shown in FIG. 6) of gas supply line 110. Morespecifically, in the illustrated embodiment, outlet orifice 172 isconfigured to be connected to mounting bracket 108 by rotating outletorifice 172 by about 45 degrees. In other suitable embodiments, outletorifice 172 may be configured to be connected to mounting bracket 108 byrotating outlet orifice 172 by less than about 90 degrees, more suitablyless than about 60 degrees, and, even more suitably, by less than about45 degrees.

Referring again to FIGS. 2 and 3, pilot guard 102 is configured toreceive gas from gas supply line 110, mix the gas with air, and directthe air-fuel mixture out of pilot guard 102 and towards thermo-electricdevice 106. Pilot guard 102 has a first end 178 defining a gas inlet 180(shown in FIG. 3), and an opposing second end 182 in which gas outlet112 is defined. Further, pilot guard 102 includes an elongate tubularbody 184 and a pilot hood 186 disposed at second end 182. When pilotburner assembly 100 is assembled, pilot guard 102 is connected to gassupply line 110 (specifically, outlet orifice 172) at gas inlet 180. Gassupplied to pilot guard 102 is mixed with air within body 184 of pilotguard 102. The air-fuel mixture is discharged at second end 182 throughgas outlet 112. Pilot hood 186 at least partially defines gas outlet112, and is configured to direct the air-fuel mixture towardsthermo-electric device 106. Pilot hood 186 is further configured tocooperate with electrode 162 of igniter 104 to generate an electricalarc and ignite the air-fuel mixture discharged through gas outlet 112.

Pilot guard body 184 has a generally tubular shape, and extends fromfirst end 178 of pilot guard 102 towards second end 182 along a centrallongitudinal axis 188 (shown in FIG. 2) of pilot guard 102. Pilot guardbody 184 defines a fluid conduit 190 (shown in FIG. 3) through which gassupplied by gas supply line 110 is fed and mixed with air from thesurrounding atmosphere. Pilot guard body 184 includes one or more airinlets 192 (shown in FIG. 3) defined therein to receive air from thesurrounding atmosphere into fluid conduit 190. As described in moredetail herein, retention elements of mounting bracket 108 are configuredto cooperate with one or more retention elements of gas supply line 110and pilot guard 102 to maintain a relative position between outletorifice 172 and air inlet 192 such that gas flowing through pilot guard102 (e.g., through fluid conduit 190) creates a Venturi effect withinpilot guard 102 to facilitate mixing of gas and air within pilot guard102. The illustrated embodiment includes a single air inlet 192,although pilot guard body 184 may include any suitable number of airinlets 192 that enable pilot guard 102 to function as described herein.

Pilot hood 186 extends from pilot guard body 184 at second end 182 ofpilot guard 102. Pilot hood 186 at least partially defines gas outlet112, and is shaped to define a directional fluid flow path for theair-fuel mixture discharged from pilot guard 102. When pilot burnerassembly 100 is assembled, pilot hood 186 extends from pilot guard body184 towards thermo-electric device 106 such that the air-fuel mixturedischarged from pilot guard 102 is directed towards thermo-electricdevice 106.

With additional reference to FIG. 7, pilot hood 186 includes an angledsparking tip 194. When pilot burner assembly 100 is assembled, sparkingtip 194 is positioned closer to igniter 104 (specifically, electrode162) than any other part of pilot guard 102 such that the electrical arcgenerated by igniter 104 is generated between electrode 162 and sparkingtip 194. Further, sparking tip 194 is configured to concentrate theelectric field induced by electrode 162 within pilot hood 186 atsparking tip 194. More specifically, sparking tip 194 is angled at anangle 196 defined by a first side 198 and a second side 200 of sparkingtip 194. First side 198 and second 200 extend from pilot hood 186towards igniter 104, and adjoin one another at sparking tip 194. In onesuitable embodiment, angle 196 is between about 179 degrees and about 10degrees, more suitably between about 160 degrees and about 15 degrees,and, even more suitably, between about 45 degrees and about 25 degrees.Thus, in some suitable embodiments, sparking tip 194 is acutely angled,and in other suitable embodiments, sparking tip 194 is obtusely angled.In yet other suitable embodiments, sparking tip 194 may be angled at asubstantially right angle (i.e., 90 degrees).

The configuration of sparking tip 194 causes the electric field inducedby igniter 104 at the surface of pilot hood 186 to be concentrated atsparking tip 194. As a result, the electrical arc generated betweenigniter 104 and pilot hood 186 is generated at approximately the samelocation on sparking tip 194 each time the arc is generated. Sparkingtip 194 thereby facilitates a relatively consistent spark path betweenelectrode 162 and pilot guard 102, and thus improves the reliability ofpilot burner assembly 100 by reducing the number of ignition attemptsneeded to ignite the pilot flame.

Referring again to FIGS. 2 and 3, pilot guard 102 is a single, unitarypiece of material. That is, pilot guard body 184 and pilot hood 186 areformed as a single piece of material. The pilot guard 102 is suitablymade of, for example, stainless steel, though other materials arecontemplated. The unitary construction of pilot guard 102 facilitatesmore efficient assembly of pilot burner assembly 100, as compared toprior systems with separate pilot guard and hood assemblies.

Pilot guard 102 is connected to mounting bracket 108 and gas supply line110 by various retention elements that enable relatively quick and easyassembly of pilot burner assembly 100 as compared to conventionalsystems. Specifically, pilot guard 102 includes a depressible retentiontab 202 (shown in FIG. 3) that permits pilot guard 102 to be insertedthrough pilot guard apertures 122, 128 in one direction, and inhibitsmovement of pilot guard 102 in the opposite direction. Further, pilotguard 102 includes locking fingers 204 (shown in FIG. 3) configured tobe received within slots 148 (shown in FIG. 4) on mounting bracket 108and prevent rotation of pilot guard 102 to maintain the orientation ofpilot guard 102 relative to mounting bracket 108 and other components ofpilot burner assembly 100 (e.g., igniter 104 and thermo-electric device106).

With additional reference to FIG. 8, retention tab 202 is connected topilot guard body 184 at a first end 206, and extends radially outwardfrom pilot guard body 184 to a second, free end 208. Retention tab 202is depressible from its relaxed position (shown in FIG. 8) towardscentral longitudinal axis 188 of pilot guard 102 (i.e., in a radialdirection) to a depressed position (not shown). Further, retention tab202 is biased towards its relaxed position such that retention tab 202returns to the relaxed position in the absence of a bending force (e.g.,after retention tab 202 traverses one of pilot guard apertures 122 or128). As shown in FIG. 8, the illustrated retention tab 202 extends fromfirst end 206 towards second end 182 (shown in FIG. 2) of pilot guard102. That is, free end 208 of retention tab 202 points towards secondend 182 of pilot guard 102. Retention tab 202 is positioned proximatefirst end 178 (shown in FIG. 2) of pilot guard 102 such that, when pilotburner assembly 100 is assembled, retention tab 202 engages second side140 of second plate 118 and inhibits movement of pilot guard 102 towardssecond end 182 of pilot guard 102. Retention tab 202 is thus configuredto permit pilot guard 102 to be inserted through pilot guard apertures122, 128 first end 178 first, and to inhibit axial movement of pilotguard 102 in the opposite direction (i.e., towards second end 182 ofpilot guard 102).

In other suitable embodiments, retention tab 202 may extend from firstend 206 of retention tab 202 towards first end 178 of pilot guard 102.That is, free end 208 of retention tab 202 may point towards first end178 of pilot guard 102. In such embodiments, retention tab 202 may beconfigured to engage first side 136 of second plate 118 when pilotburner assembly 100 is assembled. In yet other suitable embodiments,pilot guard 102 may include a retention tab positioned approximatelycentrally along longitudinal axis 188 of pilot guard 102 such that theretention tab engages one of first side 134 or second side 138 of firstplate 116 (shown in FIG. 4) when pilot burner assembly 100 is assembled.Further, although pilot guard 102 is illustrated with a single retentiontab 202, pilot guard 102 may include more than one retention tab, suchas two, three, four, or any other suitable number of retention tabs inaccordance with any of the above described retention tabs.

The illustrated retention tab 202 is formed by stamping retention tab202 out of pilot guard body 184. That is, retention tab 202 is astamp-formed retention tab. In other suitable embodiments, retention tab202 may be formed using any suitable technique that enables pilot guard102 to function as described herein.

Locking fingers 204 extend from a bottom edge 210 of pilot guard body184, and define slots 212 extending along longitudinal axis 188 of pilotguard 102. Locking fingers 204 are sized and shaped to be receivedwithin slots 148 defined by retaining protrusions 150 and lockingprotrusion 152 (all shown in FIG. 4). Slots 212 defined by lockingfingers 204 are configured to receive at least one of retainers 174 ofoutlet orifice 172, retaining protrusions 150, and locking protrusion152 therein. In the illustrated embodiment, only one of slots 212 isconfigured to receive locking protrusion 152 therein. Thus, pilot guard102 can be inserted into pilot guard aperture 128 (shown in FIG. 3) inonly one orientation (e.g., the orientation in which sparking tip 194extends towards igniter 104 and in which pilot hood 186 directs thepilot flame towards thermo-electric device 106). In other words, lockingprotrusion 152 and locking fingers 204 (specifically, slots 212 definedby locking fingers 204) facilitate assembly of pilot burner assembly 100by preventing insertion of pilot guard 102 in an incorrect orientation(e.g., an orientation in which sparking tip 194 extends in a directionother than towards igniter 104 and/or in which pilot hood 186 directsthe pilot flame in a direction other than towards thermo-electric device106).

Bottom edge 210 of pilot guard body 184 is configured to engage at leastone of retainers 174 of outlet orifice 172, retaining protrusions 150,and locking protrusion 152 to support pilot guard 102 within mountingbracket 108 when pilot burner assembly 100 is assembled. Bottom edge 210of pilot guard body 184 is also configured to engage at least one ofretainers 174 of outlet orifice 172 to restrict axial movement of gassupply line 110. The illustrated embodiment includes three lockingfingers 204, although other suitable embodiments may include more orless than three locking fingers, such as one, two, four, five, or anyother suitable number of locking fingers that enables pilot burnerassembly 100 to function as described herein.

With additional reference to FIG. 9, when pilot burner assembly 100 isassembled, locking fingers 204 are positioned within slots 148 definedby retaining protrusions 150 and locking protrusion 152 (both shown inFIG. 4). Locking fingers 204 engage one or more of retaining protrusions150 and locking protrusion 152 to inhibit rotation of pilot guard 102and maintain alignment of pilot guard 102 relative to other componentsof pilot burner assembly 100. More specifically, locking fingers 204cooperate with pilot guard aperture 128 and one or more of retainingprotrusions 150 and locking protrusion 152 to maintain the orientationof pilot guard body 184, pilot hood 186, and sparking tip 194 relativeto igniter 104 and thermo-electric device 106. Retainers 174 of outletorifice 172, retaining protrusions 150, and locking protrusion 152 areeach positioned within slots 212 defined by locking fingers 204. Lockingfingers 204 engage retainers 174 to inhibit rotation of outlet orifice172. The configuration of pilot guard 102 and mounting bracket 108thereby facilitate maintaining the spark gap between sparking tip 194and igniter 104, and further improve the reliability of pilot burnerassembly 100 by maintaining the direction of gas flow discharged frompilot hood 186 towards thermo-electric device 106.

Further, in the example embodiment, retention elements on each of pilotguard 102, mounting bracket 108, and gas supply 110 are configured tocooperate with one another to facilitate mixing of gas and air withinpilot guard 102. More specifically, retaining ledge 146 (specifically,retaining protrusions 150, shown in FIG. 4) engages retainers 174 onoutlet orifice 172 (shown in FIG. 6) to inhibit axial movement of gassupply line 110 (e.g., away from air inlet 192, shown in FIG. 3), andengages locking fingers 204 to inhibit rotation of pilot guard 102.Further, retention tab 202 engages bracket 108 (specifically, secondside 140 of second plate 118, shown in FIG. 4) to inhibit axial movementof pilot guard 102 (e.g., away from outlet orifice 172). The retentionelements on pilot guard 102, mounting bracket 108, and gas supply line110 thus cooperate with one another to maintain a relative position ofoutlet orifice 172 and air inlet 192. Moreover, in the exampleembodiment, the retention elements on each of pilot guard 102, mountingbracket 108, and gas supply line 110 cooperate with one another tomaintain a relative position between outlet orifice 172 and air inlet192 such that gas flowing out of outlet orifice 172 and through pilotguard 102 creates a Venturi effect within pilot 102. That is, when pilotburner assembly 100 is assembled, outlet orifice 172 is positionedrelative to air inlet 192 such that gas flowing through outlet orifice172 into fluid conduit 190 causes a reduction in fluid pressure withinfluid conduit 190 proximate air inlet 192, thereby facilitating mixingof air and gas within pilot guard 102.

In use, pilot burner assembly 100 is installed in a millivoltcontrolled, gas fired appliance, such as water heater system 20, toprovide an ignition source for a main burner, such as main burner 38.Pilot burner assembly 100 may be installed at the same time as mainburner 38, or may be installed at a different time than main burner 38(e.g., to replace a non-operational pilot burner assembly).

Referring to FIGS. 2-6 and 8-9, to assemble pilot burner assembly 100,thermo-electric device 106 is inserted through thermo-electric deviceapertures 126, 132, and into resilient contact with retaining ring 158(shown in FIG. 4). Resilient fingers 160 of retaining ring 158 (shown inFIG. 4) engage thermo-electric device 106, and provide a press-fitconnection between thermo-electric device 106 and mounting bracket 108.In the illustrated embodiment, thermo-electric device 106 is insertedinto bracket 108 in a first, generally upward direction indicated byarrow 214 in FIG. 3. That is, thermo-electric device 106 is insertedthrough thermo-electric device aperture 132 first and thenthermo-electric device aperture 126. In other suitable embodiments,thermo-electric device 106 may be inserted through thermo-electricdevice aperture 126 first and then thermo-electric device aperture 132(i.e., in a direction opposite to first direction 214). Thermo-electricdevice 106 is connected to controller 44 by connection 42 (both shown inFIG. 1).

Igniter 104 is inserted through igniter apertures 124, 130, and intoresilient contact with retaining ring 154 (shown in FIG. 4). Resilientfingers 156 of retaining ring 154 (shown in FIG. 4) engage igniter 104,and provide a press-fit connection between igniter 104 and mountingbracket 108. In the illustrated embodiment, igniter 104 is inserted intobracket 108 in first direction 214. That is, igniter 104 is insertedthrough igniter aperture 130 first and then igniter aperture 124. Inother suitable embodiments, igniter 104 may be inserted through igniteraperture 124 first and then igniter aperture 130 (i.e., in a directionopposite to first direction 214). Igniter 104 is connected to a voltagesource (not shown) by connection line 114.

Gas supply line 110 (specifically, outlet orifice 172) is insertedthrough pilot guard aperture 128 in second plate 118 in first direction214, and rotated about 45 degrees about longitudinal axis 176 (shown inFIG. 6). More specifically, retainers 174 on outlet orifice 172 areinserted through slots 148 defined by retaining protrusions 150 andlocking protrusion 152 (shown in FIG. 4), and outlet orifice 172 isrotated about 45 degrees such that retainers 174 on outlet orifice 172engage retaining protrusions 150.

Pilot guard 102 is inserted into bracket 108 in a second, generallydownward direction indicated by arrow 216 in FIG. 3. Second direction216 is generally opposite first direction 214.

Pilot guard 102 is inserted through pilot guard apertures 122, 128 suchthat locking fingers 204 are received within slots 148 defined byretaining protrusions 150 and locking protrusion 152 (shown in FIG. 4).That is, locking fingers 204 are inserted into slots 148 defined byretaining protrusions 150 and locking protrusion 152.

Pilot guard 102 is fluidly connected to gas supply line 110 at first end178 of pilot guard 102. More specifically, outlet orifice 172 isinserted through gas inlet 180. Retainers 174 on outlet orifice 172 arepositioned within slots 212 defined by locking fingers 204 such thatrotation of outlet orifice 172 is inhibited by locking fingers 204.

As pilot guard 102 is inserted through pilot guard aperture 128,retention tab 202 is depressed and permits pilot guard 102 to beinserted in second direction 216. Once retention tab 202 has traversedpilot guard aperture 128, retention tab 202 returns to its original,relaxed position, thereby inhibiting axial movement of pilot guard 102in first direction 214 opposite second direction 216. As best seen inFIG. 8, retention tab 202 is positioned adjacent second side 140 ofsecond plate 118 once pilot guard 102 is fully inserted through pilotguard aperture 128. Retention tab 202 engages second side 140 of secondplate 118, and thereby inhibits axial movement of pilot guard 102 infirst direction 214.

Bottom edge 210 of pilot guard body 184 is positioned adjacent retainers174 of outlet orifice 172, retaining protrusions 150, and lockingprotrusion 152. In the illustrated embodiment, bottom edge 210 engagesretainers 174 of outlet orifice 172 and locking protrusion 152 tosupport pilot guard 102 within mounting bracket 108.

FIG. 10 is a perspective view of another embodiment of a pilot burnerassembly, indicated generally at 300, suitable for use in water heatersystem 20 (shown in FIG. 1). Components of pilot burner assembly 300identical to components of pilot burner assembly 100 shown in FIGS. 2-9are identified using the same reference numerals as used in FIGS. 2-9.As shown in FIG. 10, pilot burner assembly 300 is substantially similarto pilot burner assembly 100 shown in FIGS. 2-9, except pilot burnerassembly 300 includes a gas supply line 302 having a retention element304 configured to maintain a connection between gas supply line 302 andmounting bracket 108. More specifically, retention element 304 isconfigured to engage retaining ledge 146 (specifically, retainingprotrusions 150, shown in FIG. 4)) to restrict axial movement of gassupply line 302 in a first direction, indicated by arrow 301 in FIG. 10.Retention element 304 facilitates reducing the tensile load on outletorifice 172 because retention element 304, rather than retainers 174 onoutlet orifice 172 (shown in FIG. 6), engages retaining ledge 146 whengas supply line 302 is placed under tension. Thus, a tensile loadapplied to gas supply line 302 is not transferred to outlet orifice 172.

Retention element 304 may include any suitable retention element thatenables gas supply line 302 to function as described herein. In theillustrated embodiment, retention element 304 includes a portion of gassupply line 302 having an enlarged dimension (e.g., a protrusion orridge) relative to the adjacent portions of gas supply line 302. Inother suitable embodiments, retention element 304 may include retainerssimilar to retainers 174 of outlet orifice 172.

Pilot burner assembly 300 is assembled in substantially the same manneras pilot burner assembly 100, except gas supply line 302 is insertedthrough both first and second pilot guard apertures 122, 128, and isinserted in substantially the opposite direction as gas supply line 110is inserted. More specifically, gas supply line 302 is inserted throughfirst and second pilot guard apertures 122, 128 in first direction 301,shown in FIG. 10. Retention element 304 is sized to be received throughfirst pilot aperture 122, and to engage retaining ledge 146(specifically, retaining protrusions 150, shown in FIG. 4) to inhibitaxial movement of gas supply line 110 in first direction 301. In theembodiment shown in FIG. 10, outlet orifice 172 is inserted throughfirst pilot guard aperture 122, and retention element 304 preventsoutlet orifice 172 from passing through second pilot guard aperture 128in first direction 301.

As described above, the pilot burner assemblies of the presentdisclosure utilize various retention elements to provide relativelyquick and simple assembly of the pilot burner assemblies. As usedherein, the term retention element refers to any feature of the pilotburner assemblies described herein that facilitates connecting,assembling, maintaining a connection, interlocking, or maintaining anorientation of one or more components of the pilot burner assembliesdescribed herein. Retention elements include, for example, retainingledge 146, slots 148, retaining protrusions 150, locking protrusion 152,retaining ring 154, resilient fingers 156, retaining ring 158, resilientfingers 160, retainers 174, retention tab 202, locking fingers 204,slots 212, and retention element 304.

Embodiments of the systems and methods described herein achieve superiorresults as compared to prior and systems and methods. For example,unlike known pilot burners, the pilot burner assemblies described hereininclude various retention elements that facilitate relatively quick andsimple assembly as compared to known pilot burners. In particular, thepilot burner assemblies described herein include a mounting brackethaving a retaining ledge that cooperates with retention elements on agas supply line and a pilot guard to maintain a connection between themounting bracket and the gas supply line. Further, the pilot burnerassemblies described herein include a pilot guard having locking fingersthat cooperate with retention elements on the mounting bracket and thegas supply line to maintain the connection and orientation of the pilotguard, the gas supply line, and the mounting bracket. Yet even further,the pilot guard includes a depressible retention tab that permits thepilot guard to be inserted in a first direction, and inhibits movementof the pilot guard in the opposite direction, thereby facilitating quickand simple assembly of the pilot burner assembly. Yet even further, thepilot burner assemblies described herein include a pilot hood thatincludes an angled sparking tip. The angled sparking tip reduces theneed to manually adjust the spark gap, improves the reliability of thepilot burner assemblies, and reduces the number of ignition attemptsneeded to ignite the pilot flame as compared to known pilot burners. Yeteven further, the pilot burner assemblies described herein include athermo-electric device having an internal resistance optimized formaximum power transfer and efficiency with a millivolt controller.

Example embodiments of millivolt controlled gas fired appliances, suchas water heater systems, and pilot burner assemblies are described abovein detail. The system and assembly are not limited to the specificembodiments described herein, but rather, components of the system andassembly may be used independently and separately from other componentsdescribed herein. For example, the pilot burner assemblies describedherein may be used in gas fired appliances other than water heaters,such as furnaces.

When introducing elements of the present disclosure or the embodiment(s)thereof, the articles “a”, “an”, “the” and “said” are intended to meanthat there are one or more of the elements. The terms “comprising,”“including,” “containing” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements. The use of terms indicating a particular orientation (e.g.,“top”, “bottom”, “side”, etc.) is for convenience of description anddoes not require any particular orientation of the item described.

As various changes could be made in the above constructions and methodswithout departing from the scope of the disclosure, it is intended thatall matter contained in the above description and shown in theaccompanying drawing(s) shall be interpreted as illustrative and not ina limiting sense.

What is claimed is:
 1. A power generation system for use with a gasfired appliance including a main burner and a gas supply line, the powergeneration system comprising: a pilot burner assembly for igniting gassupplied to the main burner, the pilot burner assembly comprising: athermo-electric device configured to convert thermal energy intoelectrical energy, the thermo-electric device having an internalresistance; and a pilot guard having a first end defining a gas inletand a second end defining a gas outlet, the pilot guard including anelongate body and a pilot hood disposed at the second end; and acontroller configured to receive a signal from the thermo-electricdevice and control the supply of gas to the main burner based on thesignal, the controller powered by electrical energy generated by thethermo-electric device, wherein the internal resistance of thethermo-electric device is matched to a load resistance of the controllerto facilitate maximum power transfer between the thermo-electric deviceand the controller.
 2. The power generation system of claim 1, whereinthe controller has a first load resistance in a first state and secondload resistance in a second state, and a power consumption of thecontroller is greater in the first state than in the second state. 3.The power generation system of claim 2, wherein the internal resistanceof the thermo-electric device is substantially equal to the first loadresistance.
 4. The power generation system of claim 2, wherein theinternal resistance of the thermo-electric device is between the firstload resistance and the second load resistance.
 5. The power generationsystem of claim 2, wherein the controller includes at least onecapacitor that is charged by electrical energy generated by thethermo-electric device, wherein the first state corresponds to acharging state of the controller during which the at least one capacitoris charged, and wherein the second state corresponds to a standby stateof the controller.
 6. The power generation system of claim 1, whereinthe internal resistance of the thermo-electric device is between 2 ohmsand 9 ohms.
 7. The power generation system of claim 1, wherein theinternal resistance of the thermo-electric device is between 4 ohms and8 ohms.
 8. The power generation system of claim 1, wherein the internalresistance of the thermo-electric device is between 4.5 ohms and 5.5ohms.
 9. The power generation system of claim 1, wherein the pilotburner assembly further includes a bracket comprising a first plate anda second plate spaced from the first plate, each of the first and secondplates having a pilot guard aperture defined therein, the pilot guardconfigured to be inserted into the pilot guard apertures, and whereinthe pilot guard further includes a first retention element thatcooperatively engages a second retention element on the gas supply lineto maintain a connection between the pilot guard and the gas supplyline.
 10. The power generation system of claim 9, wherein the firstretention element comprises a plurality of locking fingers extendingfrom a bottom edge of the pilot guard body, the locking fingers definingslots configured to receive the second retention element therein. 11.The power generation system of claim 9, wherein the bracket furthercomprises a third retention element that cooperatively engages at leastone of the first retention element and the second retention element tomaintain the connection between the pilot guard and the gas supply line.12. The power generation system of claim 11, wherein the gas supply linefurther includes an outlet orifice and the pilot guard further includesat least one air inlet, separate from the gas inlet, for receivingambient air therethrough, and wherein the third retention elementcooperatively engages at least one of the first retention element andthe second retention element to maintain a relative position between theoutlet orifice and the at least one air inlet such that gas flowingthrough the pilot guard creates a Venturi effect within the pilot guardto facilitate mixing of gas and air within the pilot guard.
 13. Thepower generation system of claim 11, further comprising the gas supplyline, wherein the gas supply line comprises an outlet orifice positionedwithin the first end of the pilot guard, the second retention elementcomprising a retainer extending radially outward from the outletorifice, the retainer engaging the third retention element to maintain aconnection between the gas supply line and the bracket.
 14. The pilotburner assembly of claim 9, wherein the pilot guard further comprises adepressible retention tab, the retention tab configured to permit thepilot guard to be inserted into the bracket in a first direction, andinhibit movement of the pilot guard in a second direction opposite thefirst direction.
 15. The pilot burner assembly of claim 9 furthercomprising an igniter configured to be connected to the bracket, whereinthe pilot hood comprises an angled sparking tip configured toconcentrate an electric field induced by the igniter within the pilothood at the sparking tip.